Title, intro text, Q1, Q2, Q6, test update
Q7 and Q8 add
Content update and H, I, K, L, N, O, R, S, U, V options remove
Options update and old tests fix
Track when a user wants to change a previous answer

It's possible, but very difficult, to infer this from GA flows. Explicitly track it as a custom event so we can make design decisions based on data.

* Match the existing (but broken) GOVUK.Analytics.Trackers event convention
* Using slug as action will allow looking at smart-answers by change rate
* Slug extraction is a little brittle, but:
** This is a short lived change to get some data
** It's based on existing logic that is working correctly.
New options and tests add
Content update
Update state pension calculator logic
Fix temporary test title
Merge pull request #860 from alphagov/state_pension_logic_fix

State pension logic fix